Vehicle with movable convertible top

ABSTRACT

A motor vehicle that is equipped with a movable convertible top comprising control equipment for controlling the convertible top motion and a detection device for recognition of an intervention into the range of motion of a convertible top mechanism, which is equipped with a sensor system with sensors operating with different measurement principles, wherein, when recognizing a malfunction of the detection device or when recognizing an obstruction situation, the convertible top motion is controlled in a safety mode during which the convertible top motion continues with reduced speed and power or is stopped or reversed.

REFERENCE TO RELATED APPLICATION

This application is a U.S. national phase filing under 35 U.S.C. §371 ofPatent Cooperation Treaty No. PCT/DE2003/003442, filed Oct. 17, 2003,which claims priority to German Patent Application No. 10248762.6, filedOct. 18, 2002, the entire content of all of which are incorporatedherein by reference.

FIELD OF THE INVENTION

The present invention concerns a motor vehicle with a movableconvertible top, a device for the recognition of the convertible topposition, and a detection device that is used to recognize aninterference into the range of motion of a convertible top mechanism.

BACKGROUND OF THE INVENTION

Newer convertible vehicles are often equipped with a movable convertibletop, which can be automatically moved for example from an open to aclosed position or vice versa with the push of a button. The movement ofthe convertible top is usually effected by a hydraulic drive, which inturn drives a convertible top mechanism, which includes a convertibletop linkage, wherein the convertible top linkage may be a carryingdevice for a textile roof as well as a so-called hard-top folding roofwith mainly rigid roof elements, and comprises, where applicable, acover for a convertible top compartment as well as all elements that arebeing moved in the process.

Since problems in the process of the convertible top motion such as adecelerated movement or jamming of the convertible top can be hints thatan object or a person's body part might be caught in the convertible toplinkage, and this type of obstruction situation requires an immediatereaction to avoid injury, it is common knowledge to provide a detectiondevice to recognize an interference into the range of motion of theconvertible top mechanism.

European Patent Application 0 943 473 A2 describes a motor vehicle witha convertible top that can be moved using a drive with a convertible topcontrol, wherein sensors that are in particular designed as cameras areprovided to recognize the position of the occupants in a vehicleinterior. The sensors, which are attached above the occupants, monitor asafety area between the occupants and the convertible top in addition tothe position of the occupants in their seats and are connected to aconvertible top control. As soon as the convertible top controlrecognizes that the occupants do not stay out of a safety zone below theconvertible top and therefore injuries to the occupants caused by themoving convertible top can not be ruled out, the convertible top driveis stopped.

The disadvantage of the sensors provided in EP 0 943 473 A2, which canbe cameras, infrared sensors or ultrasonic sensors is that they areoften prone to errors in regard to their signals and, in the event thatoptical sensors are used, that they can not monitor blind spots.

German Patent Application 197 23 974 A1 also describes a method toprevent foreign objects being caught in an opening that is to be closedusing a power-operated device, which operates with an opto-electronicssensor system. When a foreign object is caught in an opening that is tobe closed, the power-operated device is switched off or switched toreverse mode using a detector beam. The direction of the detector beamis continuously changed in the process, so that the detector beam movesover the area of the edge of the opening that is to be closed.

However, this type of obstruction sensor can only be implemented withsignificant effort for the movable convertible top of a convertible anddoes not offer any protection against injuries in the event of errors orsystem failure.

Practice has shown that a detection of obstructions is possible withadequate accuracy with the aid of a capacitive sensor device.

This type of obstruction sensor with a capacitive sensor system isdescribed in German Patent Application DE 198 36 056 A1, wherein thedevice that is being used to detect the obstructions, in particular whenautomatically closing convertible tops, vehicle windows or the likeincludes a capacitive sensor device, which consists of anelectroconductive transmitter surface on one side, and anelectroconductive sensor wire and at least one metal surface that ismainly potential-free on the other side of an insulator. The transmittersurface and the sensor wire are connected to an electronic analysiscircuit.

The disadvantage of these types of obstruction protection devicesoperating with a capacitive sensor system is the same as for those ofother obstruction protection devices using pressure sensors that areknown from practical applications: they react very late in the event ofan obstruction situation, in the case of pressure sensors not until theobject that interferes with the movement has made contact.

SUMMARY OF THE INVENTION

It is the object of the present invention to provide a motor vehiclewith a power-operated convertible top, which permits the most reliableand earliest detection of an intervention into the range of motion of aconvertible top mechanism possible, so that an automatic convertible topmotion takes place without injuring a person's body parts or damagingcomponents.

In accordance with the invention, this object is solved with a motorvehicle comprising a movable convertible top, control equipment forcontrolling convertible top motion and a detection device forrecognition of an intervention into the range of motion of a convertibletop mechanism. The detection device is equipped with a sensor systemwith sensors that carry out measurements based on different measurementprinciples. When recognizing a malfunction of the detection device or inthe event of an obstruction situation, the convertible top motion iscontrolled in a safety mode, during which the convertible top motioncontinues with reduced speed and power or is stopped or reversed.

The advantage of the solution in accordance with the invention is thatit ensures obstruction protection by using various sensor systems evenif there is a failure of a sensor system that operates according to acertain measurement principle or if an obstruction situation is notdetected or not detected in time. The transition into safety mode whenthe convertible top mechanism is driven, whereby the convertible topmechanism may be a convertible top linkage and a convertible topcompartment cover, if provided, with the related movable elements,ensures a reaction that is geared towards the particular operatingsituation. The reaction can consist of continuing the convertible topmovement with reduced speed or stopping or reversing the convertible topmovement.

If some of the sensors make up an optical sensor system, it is possibleto recognize an obstruction situation early on before the object thatintervenes into the range of motion of the convertible top mechanismmakes contact with the convertible top mechanism.

In doing so, it is advantageous that optical sensors can be used thatmight already exist and are used for example to recognize the occupantposition to control safety systems such as an airbag. Thus, such devicesthat are described for instance in German Patent Applications DE 198 14691 A1 and DE 199 32 520 A1 and that are used for the detection of theposition of objects and/or persons in the interior of a motor vehiclecan be used to carry out a further function.

In an advantageous embodiment, the optical sensor system may comprise anoptical light emitting and receiving device, which creates at least onedetection plane around the range of motion of the convertible top anddetects an intervention into the detection plane with the aid of areflection detection device.

The term “light” in the present sense is not only limited to the rangeof electromagnetic radiation emitted by a radiation source that isvisible to the human eye, but includes also the range of opticalradiation that is not visible to the human eye, which also includesinfrared radiation, ultraviolet radiation, X-rays, and microwaveradiation. In particular the use of microwave radiation represents anadvantageous alternative to the use of visible light within the scope ofthe present invention.

As an alternative or as a supplement, another advantageous use of theinvention is achieved when the optical sensor system is designed withimage sensors. In doing so, the vehicle interior or passengercompartment can be sensed using at least one of these optical sensorsdirected to the passenger compartment, such as a camera or a photosensoraccording to the EP0943473 A2, whereby the range of motion and themovement of the convertible top are monitored in an electronic analysisunit based on the output signals supplied by the optical sensor.

Other sensors of the sensor system that operates according to adifferent measurement principle that can be used for instance areultrasonic sensors, pressure sensors or capacitive sensors.

Part of the detection device's sensor system is preferably designedusing capacitive sensors, which permit the contact-less obstructionrecognition due to a change of the dielectric.

In order to ensure that an obstruction situation is reliably recognizedit is advantageous to provide several capacitive sensors, which areself-synchronizing in the event of a capacity change of all sensors,e.g., due to a change in air humidity. When only a selection of thecapacitive sensors that are used are responding, the probability is highthat an obstruction situation is present. The reliability of the outputsignal can be further increased by evaluating the dynamics of thecapacitance change.

Capacitive sensors are appropriately located in critical areas ofconvertible top movement, such as in the area of elements that areconnected with a hinge such as in the area of the convertible toplinkage and/or a tensioning bow and/or a convertible top compartmentcover and/or a windshield frame and/or an area next to a window.

As a matter of principle, the capacitive sensor system can be made up ofsuitable capacitive sensors—e.g., the sensors quoted in thebeginning—that are known for the particular application. However, due tothe size of the known capacitive sensors the positioning options for thesensors are often limited.

The invention also involves a capacitive sensor, which is particularlysuitable to detect an obstruction situation during convertible topmotion. The electrodes of this capacitive sensor are located on a filmmaterial that can be deformed in all directions. The dielectric iscreated by the air in this case.

This kind of sensor foil that only requires a minimum of installationspace can be attached in all areas of a mobile convertible top, wherebyit is most advantageous to attach it between a sealing section and/or atrim part and its support.

Another advantageous option for recognizing an obstruction situation isthe evaluation of a convertible top drive's power consumption.

In an advantageous embodiment of the invention the sensor system mayinclude at least one sensor that is used to measure the powerconsumption of a convertible top drive, which is connected to anelectronic analysis unit, by means of which an obstruction situation isdetectable by comparing the present current flow with mathematicallycalculated obstruction situation criteria in regard to the current flow.

The accuracy of information on the current convertible top position isof major importance in order to ensure reliable obstruction protection.In principle, known potentiometers can be used to continuously sense thetravel of the convertible top, which are attached to a pivot point of aroof part for which the position is to be detected.

It is also possible to recognize the convertible top position bymeasuring the retraction travel of the cylinders of a convertible topdrive's hydraulic system; however, it has to be observed in this casethat this type of solution requires a larger installation space and doesnot provide information on the actual position of the convertible top,but only on the cylinder's distance of travel. Therefore, a possiblydefective connection point, that is, a disruption of the connectionbetween a cylinder and the convertible top linkage cannot be detected.

Thus, in a preferred embodiment of the invention a continuousconvertible top position recognition device is provided that monitorsthe position of the convertible top; the device uses an accelerationsensor, which measures the actual acceleration in relationship to theacceleration of free fall, to calculate the position of a definedelement of the convertible top mechanism.

With the aid of these types of acceleration sensors, which are alsocalled G-sensors and which sense two axes in one plane, the longitudinalacceleration and the lateral acceleration, it is possible to determinethe longitudinal inclination and the transversal inclination of theconvertible top. The angle to the surface of the earth can be resolvedto approx. 0.2° with the aid of a very high possible resolution of theacceleration.

As a result, the use of the G-sensor makes it possible to accuratelyrecognize the convertible top position at any time and also offers highfreedom in the design of their disposition, since this type ofconvertible top position recognition can be implemented independentlyfrom convertible top kinematics.

Furthermore, these types of acceleration sensors offer the advantagethat they can also be used for other functionalities in the vehicle,such as for roll-over detection.

Additional advantages and advantageous features of the invention will bereadily understood after reading the description, the drawings, and thepatent claims.

The drawings show schematically examples of the invention, which will beexplained in further detail in the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic top view of a convertible with an open movableconvertible top, in which image sensors of a detection device accordingto the invention are shown;

FIG. 2 shows the convertible top only of the motor vehicle according toFIG. 1;

FIGS. 3 a and 3 b show courses of pixel values after calculating thedifference during image evaluation;

FIG. 4 is a schematic three-dimensional view of the motor vehicleaccording to FIG. 1, in which an optical sensor system of the detectiondevice according to the invention is shown that creates detectionplanes;

FIG. 5 shows the motor vehicle according to FIG. 3 with another sensorsystem that creates a further detection plane;

FIG. 6 is a schematic figure of a setup for a capacitive sensor systemof a detection device according to the invention;

FIGS. 7 a and 7 b show current flows for the evaluation of signals of asensor that is used to measure the power consumption of a convertibletop drive with the detection device in accordance with the invention;

FIG. 8 shows a flow chart showing the control of the convertible topmotion in normal mode and safety mode; and

FIG. 9 is a diagrammatic figure of a convertible top positionrecognition device.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a convertible vehicle 1 with a movable convertible top 2,which is shown in greater detail in FIG. 1 in open condition and foldedinto a convertible top compartment 3, and which is shown individually inFIG. 2.

The convertible top 2 comprises a convertible top mechanism 4, which canbe moved between an open and a closed position using control equipment 5that represents a convertible top control unit and electro-hydraulicconvertible top drive 6, of which only sections are shown in FIG. 2.

The control equipment 5 is designed so as to interact with a rain sensorand a key transmitter, and to start an automatic convertible top motionupon the request of the driver with the aid of a button in the vehicleor through the key transmitter, as well as when precipitation isrecognized by the rain sensor.

To be able to reliably carry out the automatic convertible top movementwithout the intervention of the vehicle user and without the user'ssupervision, an automatic detection device 7 is provided for thedetection of an interference into the range of motion of the convertibletop mechanism 4, which is here integrated into the convertible topcontrol unit 5 in terms of the electronic analysis unit.

The detection device 7 comprises a sensor system with sensors thatoperate according to different measurement principles, whereby part ofthe sensor system represents an optical sensor system 8, which is shownschematically in FIG. 1, and which is fitted with two image sensors 9,10 in the version according to FIG. 1.

In the shown embodiment, the image sensors 9, 10 are each located onwindshield frame 11 in the transition area to an A-pillar; however, analternative version is also possible, in which only one image sensor islocated in the center or where the image sensors are attached to theoutside mirrors or other suitable elements on the periphery of the motorvehicle.

In the present example, image sensors 9, 10 represent black and whitecameras, which record a vehicle interior 12 and a swivel range at therear of the convertible top 2, as shown with a viewing zone in FIG. 1for camera 9 which is positioned on the right of a vehicle in theforward driving direction.

The images recorded by cameras 9, 10 are evaluated using suitableanalysis algorithms of detection device 7. In the process, in theillustrated version the difference is determined for example between twoconsecutive images, whereby the resulting image is used to calculate thesum of the remaining pixels. An intervention into the range of motion ofthe convertible top mechanism 4 is indicated by a sudden increase aboveand beyond a defined limit value in a run of the number of pixels overtime.

In order to obtain greater independence from environmental influences itis appropriate to subtract the difference images of both cameras 9, 10from one another. When cameras 9, 10 are appropriately aligned, theresult is a difference in the dynamics of the image change between theright and the left side of the motor vehicle 1.

FIGS. 3 a and 3 b show the course of pixel values after calculating thedifference during time t. FIG. 3 a shows a pixel value course for anundisturbed convertible top motion, and FIG. 3 b shows a pixel valuecourse for a convertible top movement with an intervention into theconvertible top mechanism 4. In the shown example, the area marked with“X” in FIG. 3 b shows a clear increase in the number of pixels overtime, which represents the intervention into the convertible topmechanism 4.

An image cluster method is also suitable to analyze the images, wherebythe range of motion of the convertible top mechanism 4 is subdividedinto selected image sections and the relative changes are evaluated ineach image section.

In the event of a fault, which is detected by evaluating the imageinformation in critical areas that are defined in the software of thedetection device 7, a previously defined reaction takes place whenever afault is detected, which can consist of interrupting the convertible topmotion, reversing a partial motion or automatically moving back to thestart position.

FIGS. 4 and 5 show a further embodiment of a sensor system 8 with anoptical light emitting and receiving device 14 or 15, which, in the caseof FIG. 4, creates light planes 16, 17, 18 around the range of motion ofthe convertible top 2 on the side of the convertible top mechanism 4facing the outside of the vehicle, and in the case of FIG. 5, createslight planes 19, 20, 21 around the range of motion of the convertibletop 2 on the side of the convertible top mechanism 4 facing a passengercompartment 12.

The light emitting and receiving devices 14 or 15 can be designed in thefamiliar way with a laser as the light source as is known for instancefrom German Patent Application DE 37 00 009 A1.

When the light planes 16 to 21 are penetrated by an object or a humanbody part, a reflection deviation occurs, which is measured by suitablereflection detection devices such as a sensor and transmitted as asignal to an evaluation unit of the detection device 7. The electronicanalysis unit uses these output signals to calculate a distance and anangle of intervention into the particular light plane with the aid ofsuitable algorithms.

The presented capacitive sensor system 8 permits contact-lessobstruction recognition and is therefore particularly suited as part ofa multisensor system, such as the sensor system of the detection device7, which also comprises a capacitive sensor system 49 in addition to theoptical sensor system 8 in the shown embodiment.

FIG. 6 shows in principle a possible design of the capacitive sensorsystem 49, which has several capacitive sensors, a selection of whichare shown with the capacitive sensors 22, 23, 24, and 25 in FIG. 6.

In the shown version, the capacitive sensors 22 to 25 are each locatedin a critical area of the convertible top mechanism 4, such as in anarea of elements 26, 27 which are connected with each other byhinges-like connections as shown in FIG. 2, and which are elements of aconvertible top linkage, a tensioning bow 28, an area 29 next to awindow, an area 30 abutting to the windshield frame 11, and in anabutting area for a convertible top compartment cover 31 indicated inFIG. 1.

As shown schematically in FIG. 6, each of the present capacitive sensors22 to 25 is designed as a flat, film-like sensor, on which electrodes 32are located on a film material. The special structure of the conductortracks on this film results in a capacitive sensor, which on one side ofthe film reacts upon a dielectric change, which is air for thecapacitive sensors 22 to 25. Thus, capacitance changes when an object ora body part approaches, which is converted into analog voltage signalsin an integrated electronic circuit for further processing in thecontrol equipment 5 of the convertible top 2.

As appears from FIG. 6, the film-like sensors 22 to 25 are eachconnected to the convertible top control unit 5 via electronic analysistechnology or via electronic analysis circuits 33, 34, 35, 36, whichgenerate an analog voltage signal using the capacitance of the sensor,whereby a readjusting threshold switch 37 is provided between theelectronic analysis circuits 33 to 36 and the convertible top controlunit 5 in the depicted version. The re-adjustable threshold switch 37for instance causes, in the event of a sharp increase of air humidity inthe environment, such as in the event of contact with snow, an offset(change) of the switch point and thus an associated reduction of thesensitivity of all sensors, so that a body part such as a finger can bedetected right through the snow. The electronic analysis circuits 33 to36 allocated to the individual sensors 22 to 25 are also arranged on thefilm material.

The capacitive sensor films 22 to 25, which are mounted between sealingsor trim parts of the convertible top mechanism 4 and their support tothe extent possible, are able to detect a foreign object at a distanceof up to 60 mm for example.

To rule out that the system is being triggered erroneously due toexternal influences, the used sensors 22 to 25 are synchronized, and theplausibility of their signals is checked by the appropriate electronicanalysis device or threshold switch 23. In the event of a capacitancechange of all capacitive sensors the system assumes that theenvironmental influences have changed, whereby an obstruction situationis detected when the capacitance changes in only a selection of thecapacitive sensors, e.g., one or two adjacent sensors.

As appears from FIG. 2, the sensor system of the detection device 7comprises an additional sensor 38 for the recognition of the powerconsumption of the convertible top drive 6, which is connected to acorresponding electronic analysis unit of the detection device 7 or theconvertible top control unit 5 respectively, which checks whether anobstruction situation is present by comparing the present current flowwith mathematically calculated obstruction criteria in regard to thecurrent flow.

FIGS. 7 a and 7 b show the differences in the current flows, wherebyFIG. 7 a shows a characteristic run of current I for a certainconvertible top position that is present whereby there is nointervention into the range of motion of the convertible top mechanism4. When comparing the present current flow shown in FIG. 7 b to thecharacteristic current flow of FIG. 7 a, a deviation becomes apparent inan area marked with “Y”, which represents the characteristic change ofcurrent I. This characteristic change of current I in area Y isinterpreted by the electronic analysis unit as an intervention into therange of motion of the convertible top mechanism 4, since an increase ofpower consumption of the convertible top drive which is embodied herewith a hydraulic pump, is due to a power input into the convertible topmechanism 4 opposite to the direction of motion.

The system assumes that an obstruction situation is present aftercomparing the characteristic obstruction situation criteria that arestored in the electronic analysis unit and detecting that these criteriaapply to the present current flow. Outer boundary conditions such astemperature and battery voltage can be eliminated for the most part withthe aid of appropriate algorithms when monitoring the current.

Although legal requirements on the maximum permissible clamping force ofe.g., a maximum of 100 N can already be met during this type of currentevaluation alone, it is necessary to make contact with the objectinterfering with the movement. Thus, in the depicted version the currentis evaluated using the sensor 38 in combination with a sensor operatingbased on another effective technical principle for the plausibilitycheck or as an additional protection in areas of the convertible topmechanism 4 that are not checked.

As soon as a fault is detected in the detection device 7 or thepreviously described sensor system detects an obstruction situationduring the convertible top motion, the convertible top motion iscontrolled in safety mode shown in further detail in FIG. 8, in whichthe convertible top motion continues with reduced speed and power, isstopped, or reversed in part or completely.

As appears from the flow chart in FIG. 8, an automatic start of theconvertible top motion is triggered in order to close the convertibletop in a first step S1, when a defined amount of water is detected by arain sensor.

After the start of the automatic convertible top motion, it is checkedin a second step S2, whether the present optical sensor system 8 isfunctional. If the system is functional, a processing function S3defined for normal mode is started, in which the convertible topmechanism 4 is driven with maximum power and speed.

In the process, an inquiry function S4 constantly checks, whether theconvertible top 2 has already reached the final position. If this is thecase, the system proceeds with a processing function S15 that ends themonitoring function; otherwise the convertible top 2 is kept in closingmotion with the aid of a further processing function S5, whereby thesystem permanently uses an inquiry function S6 to check during themotion, whether an obstruction is detected by the optical or thecapacitive or another sensor system.

In the event of a positive inquiry result of inquiry function S6, inother words when an obstruction situation is detected, the convertibletop motion is stopped at first by means of a subsequent processingfunction S7, and a waiting time is started. An inquiry function S8,which is also called a “Timeout” function, is used to check while theconvertible top motion is stopped, whether the obstruction situation isstill present.

If the obstruction situation no longer applies, the system returns toinquiry function S4 in order to check, whether the final position ofconvertible top 2 has been reached; otherwise a continued convertibletop motion is permitted via function S5.

If the check result of inquiry function S8 is that the obstructionsituation is still present after the waiting time has ended while theconvertible top motion is stopped, the system is started in safety modeby a processing function S9. This safety mode is also started if inquiryfunction S2 detects that optical sensor system 8 is not functionalimmediately after the automatic convertible top motion starts.

After starting in safety mode, an inquiry function S10 checks, as innormal mode, whether convertible top 2 has reached its final position.If this is already the case, the system proceeds with function S15 whichends the monitoring function.

Otherwise, the convertible top motion continues via a processingfunction S11 with reduced speed v_min, whereby an inquiry function S12is used to check during this decelerated convertible top motion, whetheran obstruction situation is detected via the capacitive sensor system orvia current evaluation. If this is not the case, the system returns toinquiry function S10, and the convertible top is closed with reducedspeed until it has reached its final position.

If an obstruction situation is detected by inquiry function S12 insafety mode, the convertible top motion is stopped or reversed by aprocessing function S13 depending on the severity of the obstructionsituation, whereby a waiting time is started in a further step S14,during which the system checks whether the obstruction situation isstill present. As long as this is the case, the convertible top motionremains stopped or reversed.

With the aid of the safety mode it can be ruled out that the automaticfunction of the convertible top motion is not started due to a singleerror and that the vehicle is possibly damaged as a result. On the otherhand, an adequate reaction is triggered immediately in the event of aclear obstruction situation.

A continuous convertible top position recognition 39, which is shown inprinciple in FIG. 9, is provided to ensure the most reliable evaluationof the present signals possible.

The convertible top position recognition 39 is formed of severalacceleration sensors 40, 41, 42, each of which are located on a certainroof element, e.g., the acceleration sensor 40 on a front roof segment43, the acceleration sensor 41 on a center roof segment 44, and theacceleration sensor 42 on a rear roof segment 45. The accelerationsensors 40, 41, 42 represent so-called G-sensors, which measure andindicate the current acceleration relative to the acceleration of fallor normal g force. The earth's acceleration of free fall of 9.81 m/s²corresponds to 1 G (G=gravitation). The acceleration sensors 40, 41, 42not only measure the acceleration of the element onto which each of themis attached, but also the incline in relationship to the earth'ssurface.

The acceleration sensors 40, 41, 42 that are used here operate in arange of 0 G up to a maximum of 10 G and provide an output voltage,which is linear to the acceleration value.

The acceleration sensors can be positioned anywhere on the convertibletop 2, whereby attention is to pay only to the orientation in a definedco-ordinate system.

As appears from FIG. 9, the acceleration sensors 40, 41, 42 on theconvertible top 2 are connected via a suitable wiring harness or ahighly-flexible microstrip to an electronic analysis unit 46, whichanalyzes the sensor signals and calculates a relative position using theindividual positions. The calculated relative position of theacceleration sensors 40, 41, 42 or the components that carry them istransmitted to the convertible top control unit 5 by the electronicanalysis unit 46 via a bus system such as a CAN bus 47.

In the embodiment described here, a further acceleration sensor 48 thatis designed as a G-sensor is located in the convertible top control unit5; the sensor determines the location or incline of the motor vehicle 1in the defined co-ordinate system, to which the acceleration sensors 40,41, 42 are allocated as well. The convertible top control unit 5 usesthe relative position and the present information on the vehicle inclineto calculate the current position of the convertible top 2.

Advantageously, the typical convertible top final position switches areno longer required when the convertible top position recognition 39 isused, since a corresponding pulse is put out by the acceleration sensors40, 41, 42, when the convertible top 2 has reached a limit stop, inother words when it is fully closed or open; whereby, the sensors aresubject to powerful negative acceleration.

Moreover, with the continuous convertible top position recognition 39 itis possible to implement an adaptive self-learning control of theconvertible top motion, which may be realized for instance by manuallydriving to individual defined convertible top positions one time.

In doing so, the convertible top position can be determined with higheraccuracy, which in turn improves the recognition of an obstructionsituation during convertible top movement.

1. A motor vehicle with a movable convertible top, comprising: controlequipment for controlling movement of the convertible top; and adetection device for recognizing an intervention into the range ofmotion of the convertible top, the detection device including a sensorsystem having a plurality of sensors operating according to differentmeasurement principles; the control equipment being operable, when aproblem is recognized with the detection device or in the event of anintervention situation, to control the convertible top in a safety modeselected from the group consisting of continuing to move the convertibletop with reduced speed and power, stopping movement of the convertibletop, and reversing movement of the convertible top, the particularsafety mode being selected dependent on the particular operatingsituation and the detected intervention situation.
 2. A motor vehicleaccording to claim 1, wherein the sensors include an optical sensorsystem.
 3. A motor vehicle according to claim 2, wherein the opticalsensor system includes an optical light emitting and receiving device,which forms at least one light plane around the range of motion of theconvertible top and detects an intervention into the light plane withthe aid of a reflection detection medium.
 4. A motor vehicle accordingto claim 3, wherein a laser is used as the light source of the tightemitting and receiving device.
 5. A motor vehicle according to claim 3,further comprising an electronic analysis unit, which uses outputsignals of the reflection detection medium to calculate the distanceand/or the angle of an intervention into the light plane.
 6. A motorvehicle according to claim 3, wherein at least one light plane is formedon a side of the convertible top mechanism facing a passengercompartment.
 7. A motor vehicle according to claim 3, wherein at leastone light plane is formed on a side of the convertible top mechanismfacing the outside of the vehicle.
 8. A motor vehicle according to claim2, wherein the optical sensor system includes at least one image sensor,which monitors the range of motion of the convertible top mechanism. 9.A motor vehicle according to claim 8, further comprising an electronicanalysis unit that detects an intervention into the range of motion ofthe convertible top mechanism by difference image analysis.
 10. A motorvehicle according to claim 8, wherein at least one image sensor is alsoallocated to a device that monitors the vehicle interior and/or theposition of occupants.
 11. A motor vehicle according to claim 1, whereinthe sensor system includes at least one capacitive sensor.
 12. A motorvehicle according to claim 11, wherein the sensor system includesmultiple capacitive sensors and an intervention situation is detectedwhen a selection of several of the multiple capacitive sensors isresponding.
 13. A motor vehicle according to claim 11, wherein at leastone capacitive sensor that is used to recognize an interventionsituation is located in the area of elements that are connected withhinges of a convertible top linkage and/or a tensioning bow and/or aconvertible top compartment cover and/or a windshield frame and/or anarea next to a window.
 14. A motor vehicle according to claim 11,wherein the capacitive sensor that is used to recognize an interventionsituation is located between a sealing section and/or a trim part andits support.
 15. A motor vehicle according to claim 11, wherein thecapacitive sensor comprises a film with electrodes located on foilmaterial.
 16. A motor vehicle according to claim 15, wherein air is thedielectric of the capacitive sensor.
 17. A motor vehicle according toclaim 11, wherein the capacitive sensor is connected to an automaticallyreadjusting threshold switch.
 18. A motor vehicle according to claim 1,wherein the sensor system includes at least one sensor for detecting thepower consumption of a top drive, which is connected to an electronicanalysis unit, by means of which an intervention situation can bedetected by comparing the present current flow to a characteristicchange in the current flow or by using mathematically calculatedintervention criteria.
 19. A motor vehicle according to claim 2, whereina safety mode is started when a fault is recognized in the opticalsensor system.
 20. A motor vehicle according to claim 1, wherein in anormal mode the function of the sensor system is checked, and if thesensor system is found to be functional, a waiting time is started whenan intervention situation has been recognized and the soft top motion isstopped and/or reversed; and wherein the system checks during thewaiting time whether the intervention situation is still present, andwherein a safety mode is started if the intervention situation is stillpresent.
 21. A motor vehicle according to claim 1, wherein a processingfunction is started in a safety mode for closing or opening theconvertible top with reduced speed, during which the system uses aninquiry function of an electronic analysis unit to check whether anintervention situation is present, wherein a processing function thatstops and/or reverses the convertible top motion is started if theresult of the inquiry is positive.
 22. A motor vehicle according toclaim 1, wherein the reaction whether to continue the convertible topmovement with reduced speed or to stop or reverse the convertible topmotion takes place in relationship to the intervention obstruction thatis being recognized.
 23. A motor vehicle according to claim 1, whereinafter an automatic start of the convertible top movement an inquiryfunction is started for a fault in the detecting device or for detectingan intervention situation.
 24. A motor vehicle according to claim 1,wherein a continuous convertible top position recognition is provided tomonitor the position of the convertible top, which determines theposition of a defined element of the convertible top mechanism using anacceleration sensor, which measures an actual acceleration inrelationship to the acceleration of free fall.
 25. A motor vehicleaccording to claim 24, wherein several acceleration sensors are locatedon elements of the convertible top mechanism and connected to anelectronic analysis unit, which uses the signals of the accelerationsensors to calculate a relative position, which, together with thepresent information on the vehicle incline, results in the presentconvertible top position.
 26. A motor vehicle according to claim 1,wherein the control equipment for the control of the convertible topmotion is equipped with a further acceleration sensor that is used todetect the vehicle's inclination.
 27. A motor vehicle according to claim1, wherein the sensor system includes a rain sensor.